Body fat questions...

[Adventure Girl]

The only method to get an absolutely accurate measurement of body fat percentage is...
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an autopsy.

[CorsairMac]

ooooo - do I need to schedule that with my doctor?

(ok - I'm sick and my world is happy)

[Helen]

ooooo - do I need to schedule that with my doctor?

(ok - I'm sick and my world is happy)

You better nooooot
Anyway ... what do you think of those body fat measuring scales ?

[btchance]

I heard about 12% being a serious health treshold, but I haven't researched this. I'm kind of worried too. Let me know what information you find... and what we should do about it.

Okay, as far as what I have found out is that it varies for everyone. Women have 10-12% essential body fat (breasts, hips, reproductive) and you should definately not go below that. Women who aren't athletes are recommended to be in the 21-33% range. Trained athletes often fall in between the two.

When problems arise as far as losing bone mass, period irregularities, etc, is different for each person (different set points). Losing body fat at a fast rate usually causes problems at a higher body fat percentage, but if you lose at a slower weight you can usually go down to a lower set point. Basically, puting your body under too much stress (emotional of physical) can create problems. There's no clear cut answer.

Some doctors recommend putting women who start having menstrual irregularities on the pill as it has been suggested to counteract some of the problems. However, you don't know if they get really low and would stop having them all toghether, so this is a little contorversial. They also recommend exercising less, eating healthy (ie not restricting your diet at all) for 6 months to correct the problem.

If anybody has any other info, let me know as there are still alot of holes in this.

[btchance]

Really ? Why is that ? Women who aren't athletes can still have a lower body fat percentage just by following a good diet program.

I'm not really sure, that's just what I found from numerous sources, and it seems to be the universal values. I don't think that it's a problem to be a little lower than that, it's just not required to be healthy, especially if you're trying to get pregnant. Not completely sure though.

[Grog]

I'm not really sure, that's just what I found from numerous sources, and it seems to be the universal values. I don't think that it's a problem to be a little lower than that, it's just not required to be healthy, especially if you're trying to get pregnant. Not completely sure though.

Right. I am not sure in making that link, but I think that fat is closely related to hormones production (oestrogens in particular) (which explains the current surge of breast cancer... in men!! very fat ones, that is), hence the potential problems for a women trying to become pregnant if her body fat gets lower than a certain level.

[runnergirl]

Low bodyfat through diet alone doesn't really work all that well. Without excercise, women don't really have much muscle, so someone with little muscle and low bodyfat looks like a runway model. All angle, no curve, no nice "cut" looking arms.

Most slender women (thin, but not runway model thin) actually have high bodyfat percentages. I wear an 8/10 and have 20% bf, my best friend (totally sedentary) wears a 2/4 and has 30% bodyfat, but she looks thinner.

[Yasmin]

Hi runnergirl, Yasmin here. I think the genetic component is the over-riding factor. Don't hate me, but I'm at the other end of the body fat spectrum (lucky to score 9%). I'm minute, but not as small as my mum was.This has it's own disadvantages as I lose power exponentially below a certain weight, especially on the long, flat stretches. Our bodies are engineered differently & that's why different people are better at some sports rather than others (I'd be embarrassing at female rugby or high jumping (short in stature)). You're out there running & cycling. No doubt you watch your nutrition. Will you be better at hill climbs minus the 7 lbs? YES. I cycle with a professional cyclist & he maintains that every ounce counts on the hills.
I wish you all the best & support your efforts. Good on ya.

So I got measured at 21% with calipers, which seems about right. I did the math, and to get to 17 or 18% I need to lose about 7 lbs of fat.

For those who have low bf, is it genetic? Do you have to work to maintain that #?

All other things being equal, is the effort to get down to a "competative" bf worth it for racing, will 7 lbs alter my ability to climb? (Bikemomma, pink kona?)

[Yasmin]

I have a question in the opposite direction, how do you know you are too low on body fat, and what is an approximate number?

I ask this because 6mo ago I was measured by the nutrition doctors at the university at 17%, while their recommended bottom number was 21, although they didn't think 17 would be a problem. I have since started exercising a lot more, and have dropped down a couple of sizes without losing any weight or eating differently. Now I have started to have irregular periods, which the doctors attribute to stress, but I don't know about that as I have been similar stress levels for years, and this actually started during a break from most of the stress. This is worrisome to me because I already have pretty small bones. When I broke my arm in multiple places when I was 20, they actually did a bone density scan because the density looked pretty light on x-ray, and when they operated, the surgeon said my bones were the size of an 11yo, so this is definately something I'm worried about.

When you start missing periods & are nowhere near menopause you can assume your body fat is getting too low. I know because I struggle with this problem myself. Eat, my dear, eat. Your body is putting on muscle & replacing the fat. Even though the scales read the same it sounds like this is what's going on. Muscle will have you burn up more energy...good if you want to lose weight, bad if you're trying to maintain. Don't be afraid of the food, your body is telling you it needs it.An example for you: last week I cycled 525km because I'm in training for a major 200km hill ride event in Jan 06. I wear a heart-rate monitor which tells me how much energy I burn up. For me to maintain at 50kg (112lbs) I require about 4,000kcals/day. This is double the average. If I fall below 50kg I lose energy & my periods mess up.
If you're at risk of osteoporosis (thin bones) the last thing you want your body thinking is that you're starving it because it will take calcium & minerals from your bones. Vicious circle.
Good luck!
Yasmin.

[Helen]

A few years ago .. I tried to lose some weight by not eating enough and starving myself every day.

I am sure you didn't quite starve yourself every day.
But if you really did that, then its quite amazing you only escaped with a low level of calcium and not other dangerous results.

[btchance]

A few years ago .. I tried to lose some weight by not eating enough and starving myself every day. The result was in a rapid drop of calcium which I am still trying to get it up to the normal levels. Eat as much as you need or you'll end up in a vicious circle (as Yasmin said) that will take you nowhere.

That's what's confusing to me right now. Whenever I'm hungry, I eat, so I'm not depriving myself, and I'm taking calcium and iron supplements (low iron levels can also cause irregular periods.) I think I need to write down what I eat everyday for a week to get an idea of how much I'm actually eating and go from there.